1. Field of the Invention
This invention relates to filtration systems, and more particularly relates to a coalescing filter assembly to reduce liquid pooling therein.
2. Description of the Related Art
Diesel engines require less maintenance and generate energy more efficiently, with less carbon dioxide emissions, than gasoline-powered engines. As a result, more than thirteen million diesel engines in the United States provide power for a wide range of vehicles and equipment including heavy-duty trucks, buses, trains, large ships, electricity generators, excavators, cranes, and agricultural equipment.
Diesel emissions, however, are more harmful to human health on a per-vehicle basis than emissions from similar gasoline-powered engines. Indeed, even though diesels comprise only about five percent (5%) of on-road vehicles in the United States, on-road diesels released 3.4 million tons of nitrogen oxides (NOx) in 2002, accounting for thirteen percent (13%) of all U.S. NOx emissions.
Accordingly, the Environmental Protection Agency (“EPA”) has finalized regulations requiring substantially more stringent emissions limits for on-road heavy-duty diesel engines, where crankcase gases are included as part of the regulated diesel engine emissions. While various types of filters have been engine-mounted in tight spaces for many years, the new EPA emissions regulations require that crankcase ventilation systems, exhaust gas recirculation (“EGR”) systems, and other components also be engine-mounted.
Engine surface space is inherently limited. Accordingly, compliance with the new EPA emissions regulations requires that engine-mounted devices overcome challenging packaging and mounting constraints. For example, conventional coalescing filter assemblies include void spaces in front of the filter element that tend to collect oil and other liquid and solid contaminants before filtration. The volume of liquid collected in those spaces may flood portions of the filter and cause oil leakage during vehicle operation. Additionally, liquid accumulated in such voids may spill out when the filter is replaced or the engine is otherwise serviced, rendering otherwise simple servicing procedures both difficult and messy. These problems are exacerbated by the increasingly limited working space available for accessing engine-mounted devices subject to the new EPA regulations.
What is needed is thus an engine-mounted coalescing filter assembly that reduces oil leaks and spills during operation and servicing while substantially maintaining filter performance and efficiency. Beneficially, such an engine-mounted coalescing filter assembly would also facilitate mounting and packaging requirements under the new EPA regulations. Such a coalescing filter assembly is disclosed and claimed herein.